Trouble, their middle name

Harry Potter - J. K. Rowling
F/M
G
Trouble, their middle name
Summary
Yelena Potter is going to Hogwarts for the first time, after leaving Ilvermorny. She is excited, because her cousin, James Potter, had talked to her about it. He is now a fifth year and can't wait to show his "little sister" the school and also his friends. James promised her that he would keep her safe and help her find good friends. He and Sirius will make sure that she won't talk with the wrong side, or people who wish to join the Dark Lord. Little did they know that she was starting to talk with THE Severus Snape.
Note
I thought it would be a good idea to have more fan fics with Severus back when he was younger. I may or may not make more than only one chapter... BUT we don't know YET. I don't have an idea at the moment but I'm pretty sure that I will think more about it. A little remider that english is not my first language :/. Alright then, hope you like the story :D.

Four days before school started. Yelena was excited but scared at the same time. She was glad that she left Ilvermorny. Students weren't the best there. Yelena felt lonely and to make it worse, a group of girls bullied her for spending time at the library. Since she didn't have friends she thought that books were here only escape. At the bright side she has James and his friends, which she doesn't know them yet. Her parents bought her everything she needed for this school year. Yelena was a pure-blood, but she and her family had respect for half-bloods and muggle-borns.

It was the big day. She went with her mother at Platform 9¾ at King's Cross Station, where she was supposed to meet James. A hand reached her shoulder and she got scared for a second, only to see Jamie smirking at the girl.

"Long time no see, huh little sis?"
"Indeed", - she said hugging him.
"Okay okay, we should go now before all the seats are taken by other people.", - he said grabing her hand so they wouldn't get lost in the crowd.
When they were searching for compartments, James heard Sirius from the other side whistling at him. He turned his head and saw Sirius pointing at an empty compartment. James smiled and went to him with Yelena.

"Who is this beautiful young lady that you got James?", - Sirius asked while watching her closely.
"Mate she's-"
"I am his cousin, and you are?", - she asked as she watched two other boys staring at her. One had scars all over his face and amber eyes and the other guy was chubby and had blue eyes.
"Sirius... Sirius Black in your service m'lady.", - he said as she watched him with confusion.
She rolled her eyes as she saw the two guys look at her with shock.
"Since you now know my name, can i know your names?", - she asked as she was watching them closely.
The guy with the scars coughed and started to say.
"Remus Lupin and he is Peter Pettigrew." - Remus said while looking at his feet.
"Nice to meet yall." - Yelena said feeling a bit weird. Remus seems shy and Sirius seems flirty.